Coverity: Fix a few uninitialized vars.

ipc/ipc_channel_reader.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ipc/ipc_channel_reader.h"
 
 namespace IPC {
 namespace internal {
 
 ChannelReader::ChannelReader(Channel::Listener* listener)
     : listener_(listener) {
+  memset(input_buf_, 0, sizeof(input_buf_));
 }
 
 ChannelReader::~ChannelReader() {
 }
 
 bool ChannelReader::ProcessIncomingMessages() {
   while (true) {
     int bytes_read = 0;
     ReadState read_state = ReadData(input_buf_, Channel::kReadBufferSize,
                                     &bytes_read);
@@ skipping 62 matching lines @@
   input_overflow_buf_.assign(p, end - p);
 
   if (input_overflow_buf_.empty() && !DidEmptyInputBuffers())
     return false;
   return true;
 }
 
 
 }  // namespace internal
 }  // namespace IPC